1. Field
Apparatuses and methods consistent with exemplary embodiments relate to a magnetic resonance imaging (MRI) apparatus and a control method thereof in which a distortion of a gradient magnetic field due to eddy current is compensated for.
2. Description of the Related Art
Magnetic resonance imaging system images the density and physiochemical characteristics of atomic nuclei by generating nuclear magnetic resonance of hydrogen atoms in a human body using a magnetic field which is not harmful to the humans, and radio waves which are a non-ionizing form of radiation.
In more detail, the MRI apparatus images an object by converting energy discharged from atomic nuclei into a signal by supplying a specified frequency and energy to the atomic nuclei in a state in which a specified magnetic field is applied to the bore of a gantry.
In order to execute imaging of the object, a magnetic field gradient is formed within the gantry. The conductors and coils are mounted in the bore of the gantry to form the gradient magnetic field, and when a current pulse is applied to the coils, eddy currents may be generated and thus the gradient magnetic field may be distorted.
Distortion of the magnetic field gradient may be compensated by a method in which a pre-emphasis of a portion of the current pulse which is assumed to be distorted is executed. A pre-emphasis volume, i.e., a compensation volume, is determined by applying a test gradient waveform. In the related art, the compensation volume is determined by assuming that the applied test gradient waveform is the ideal step function. However, the applied gradient waveform differs from the ideal step function due to the physical limitations, and thus, the accuracy of the compensation volume may be compromised.